Parasiticidal spray oil composition



July 1s, 1939.

VAPOR L|N E TEMP. AT 3.5 MM. PRESSURE A. L. L'YMAN 2,166,500

FARASITICIDAL SPRAY O IL COMPOSITION Filed Dec. 19, 1936 Y 40 woo DISTILLED [m/enior Ar zzr L. Zymzzzz Patented July 18, 1939 PATENT OFFICE PARASITICIDAL SPRAY OI L COMPOSITION Arthur L. Lyman,'Bcrkeley, Calif., assignor to Standard Oil Company of California, San Francisco, Calif., a corporation of Delaware Application December 19, 1936, Serial No. 116,827

10 Claims.

This invention relates to parasiticidal spray oil compositions for the control of insect and fungus pests on growing vegetation and to methods of preparing such compositions.

This applicatiori is a part continuation of my application for United States Letters Patent Serial No. 653,272, filed January 24, 1933.

It has been the aim of this branch of the insecticidal and fungicidal art to provide materials which, upon proper application to growing plant foliage, would fulfill their insecticidal and fungicidal purposes without damage or injury to the foliage or prejudice to fruition. Of late years this aim or ideal has been closely approximated by the controlled use of highly refined petroleum oils, either in emulsified or diluted form or in very finely divided spray or mist form, and such highly refined petroleum oils are now in wide and accepted use on the most delicate plant foliage during the growing seasons. The satisfactory use of these highly refined petroleum oils has been made possible by the discovery that certain constituents, of crude or moderately refined naturally occurring petroleum oils, notably aromatic and unsaturated hydrocarbons, sulfur compounds and organic acids, are distinctly injurious to growing plant foliage, and that the removal of these types of harmful or phytocidal compounds from petroleum oils provides an oil that may be used with safety. Unfortunately 'these harmful types of compounds, although present in petroleum oils in but relatively small proportions, are exceedingly difficult to remove, and recourse has perforce been had to drastic chemical treatment, as with strong sulfuric acid, or to the equally drastic selective solvent refining types of treatment, the latter followed in many cases by treatment with strong sulfuric acid, for their removal.

Of the several types of compounds enumeratedabove as those considered phytocidal by the parasiticidal art, the unsaturated hydrocarbons as a class are the most difficult to remove from crude petroleum oils or their distillates. Thus in the ordinary preparation of theseoils for insecticidal uses the measurement of their unsaturated content is considered of-first importance, for by the time the unsaturated content hasbeen reduced to an acceptable figure, the oil is already sufficiently free of other harmful types of compounds to be used with safety on growing plant foliage. In the trade, the absence of harmful types of compounds is recognized and measured by the term unsulfonated residue,--the percent by volume of an oil remaining inert to treatment with four times its volume of 37N H2SO4 for one hour at 100 C.,-the degree of freedom from unsaturated or sulfonatable hydrocarbons increasing as unsulfonated residue increases and a complete freedom being recognized by the term unsulfonated residue 100%. The significance attached to freedom from unsaturated or sulfonatable constituents in a parasiticidal mineral or petroleum oil is legally recognized in many areas, to the extent that such oils when sold for use in pest control during foliage growing or fruition seasons,-whether or not admixed with other materials, must be labelled with the minimumguaranteed percentage of unsulfonated residue. In arid and semi-arid regions, petroleum oil spray manufacturers do not now ordinarily market an oil for summer use with an unsulfonated residue below about and many of the oils intended forsummer use have unsulfonated residues of 97-100%.

The difficulty and expense involved in the preparation of oils of such high purity from naturally occurring crude petroleums or their distillates will be appreciated by reference to the fact that oils with unsulfonated residues of 100% are of essentially whiteoil grade, and that oils as highly refined as those of mineral seal and transformer oil quality have unsulfonated residues as low as 90 to 92%. Very considerable amounts of strong sulfuric acid or equivalent selective solvent agents are required in their preparation, treating yields are low, and large amounts of acid sludge or solvent extracts, etc., must be disposed of.

It has now-been found that the summary clas sification of any and all unsaturated hydrocarbons as phytocidal, that is, as harmful or injurious to growing plant foliage, is erroneous, and that, while some types of unsaturated hydrocarbons may be and undoubtedly are phytocidal, at least one type is altogether harmless and therefore to be considered as safe for summer spray usage as are the most highly purified mineral oils of natural origin. In particular, it has been found that aliphatic mono-olefines, an acyclic class of unsaturated hydrocarbons characterized by the presence of one double, unsaturated or ethylene bond, may be used on growing plant foliage with a safety equal to that of petroleum oils of white oil grade, and that, moreover, these hydrocarbons of the aliphatic olefine type are insecticidal and fungicidal to a degree equal to or superior to those of the naturally occurring oils.

unsaturated hydrocarbons must be so completely While it is not definitely understood why the removed from a naturally occurring oil or distillate before itcan safely be used on foliage in the growing season, in view of the now discovcred safety attending the use ofunsaturated hydrocarbons of the aliphatic olefine typ it may be pointed out that incrude petroleums and their distillates there is a great variety of types of unsaturated and aromatic compounds, some of which are more or less easily polymerizable or oxidizable to resinous or asphalty bodies and organic acids or oxygen-containing derivatives: it

is at least possible, if not probable, that the polymerization or oxidation products of certain of these unsaturated and aromatic hydrocarbons are the actual agents harmful to plant foliage. However this may be, it has been found that the aliphatic olefines as a class do not polymerize or oxidize to give resinous or asphalty bodies or harmful oxygen-containing derivatives in the manner characteristic of those naturally occurring petroleum oils which contain an appreciable proportion of "unsaturated hydrocarbons or which have a low unsulfonated residue. In any case, no harm results from their use as parasitioides on growing plant foliage.

It has been recognized that hydrocarbons of too low a viscosity are harmful to many types of growing foliage, by reason of their too great penetrability of growing plant tissues; furthermore, it has long been understood that the efiectiveness of hydrocarbons as parasiticides increases as their viscosity increases, but it has also been understood that hydrocarbons of too low a volatility or phatic mono-olefines asa class provide a wider range of viscosities and a higher viscosity for a given vo atility or boiling point range than do the hydrocarbons of natural petroleum origin when the latter are refined to usual spray oil quality and, inasmuch as they are entirely unsaturated, it will be evident that their application for parasiticidal purposes is extraordinarily advantageous in that their high viscosity, high volatility and entirely unsaturated character combine in a single oil the ideal requirements of a parasiticide of this class, namely, high parasiticidal effectiveness and low phytocidal propensities, as now ascertained.

The aliphatic olefine spray oils described herein, an acyclic class of hydrocarbons characterized by the presence of one double or unsaturated carbon to carbon bond, may be prepared in a variety tions of the desired viscosity or boiling point range. I

Suitable olefine-containing gases or low boiling point liquids for the preparation of such olefine spray oils are those obtainedin thepyrogenetic cracking of high boiling point petroleum oils for the production of niotor fuels, as in the ordinary cracking processes. In exemplification of such methods of preparing satisfactory olefine spray oils:

Example 1.A liquefied normally gaseous cracked petroleum distillate fraction, composed of about volume percent of butane plus normal and iso-olefines, 14 volume percent of propane plus propylene, and smaller amounts of bothlower and higher boiling hydrocarbons, was treated with sodium plumbite solution for the removal of hydrogen sulfide and mercaptans and was thereafter charged in increments to a reaction vessel where it was agitated with anhydrous aluminum chloride as a polymerization catalyst. The time required for substantially complete polymerization of the olefines was about onehalf hour. During thepolymerization reaction a considerable amount of heat was evolved; a reflux condenser connected to the reaction chamber was used to abstract this heat and control the temperature and pressure during the progress of the polymerization reaction, as well as to return olefine vapors for complete reaction. About 10 U. S, gallons of polymers were produced per pound of aluminum chloride used (about 83 liters polymers per kilogram aluminum chloride). An aluminum chloride tar and an oily liquid appeared as immiscible layers; the aluminum chloride tar was removed, and the mixture of olefine polymers and inert low boiling point saturated hydrocarbons was washed with water and charged to a still in which the low boiling point saturated hydrocarbons were vaporized. The olefine polymers thus produced had an initial boiling point of about 200 F. (about 93 C.) at atmospheric pressure and an end boiling point above 600 F. (above 315C.) at a pressure of 10 millimeters of mercury. Upon fractionation of these polymers for the production of an olefine spray 011, about 47.5 volume percent of an oil was obtained which had a gravity of 37-38 A. P. I. (specific gravity 0835-0840 at 15.56 C.) and a boiling point range between 235 and 500 F. (between 113 and 260 C.) at 3.5 millimeters of mercury pressure. This oil had an unsulfonated residue of about 8%, an empirical formula CnHZn, and was composed of aliphatic mono-olefines, in the substantial absence of aromatic, cyclic or unsaturated hydrocarbons of other types.

Example 2.--A gas obtained in the thermal cracking of petroleum oil, all of whose constituents were gaseous at atmospheric temperature and pressure, containing about 27% of monoolefines, was bubbled-through a suspension of anhydrous aluminum chloride in petroleum ether at atmospheric temperature and pressure. An aluminum chloride tar and an oily liquid appeared as immiscible layers. These layers gradually increased in volume until, before the activity of the catalyst had appreciably diminished, about 8 gallons of polymers had been produced per pound of catalyst (about 67 liters polymers per kilogram of catalyst), exclusive of the petroleum ether originally present as carrier. The gaseous olefines were substantially completely polymerized. The petroleum ether originally present as carrier, together with the inert saturated hydro- 'Were formed from a mixture of normal and isobutenes, with anhydrous aluminum chloride as catalyst, at four different and controlled polymeriz'ation temperatures, namely, 60, and 200 F. 51.7, 65.6 and 933 C., respectively). From the results there shown it will be observed that there is a definite increase in yield of lower boiling point polymers as the polymerization temperature is increased, and for this reason it is preferred that polymerization temperature be held slight y above atmospheric. merely in order that greater yields of olefinic hydrocarbons may be obtained within the suitable spray oil range. Polymerization temperatures should.not be allowed to go appreciably over about 350 F. (176.7 0.). however, for at such temperatures, when anhydrous aluminum chloride is the polymerizing agent used, decomposition of the polymers with the'production of low boiling point hydrocarbons begins to be apparent.

In the tabulation below are presented the physical characteristics of two of the olefine oils found suitable for use as parasiticides. pre ared in t e manner described. in comparison with the physical characteristics of a highly refined naphthene base petroleum oil now in wide and highly acceptable use for the same purpose.

10 unsul- Oleilnel Oleflnel spray 01 spray m 'h fi No. 1 No. 2 base sway oil Distillation. at 3.5 mm. Hg

pressure F. C'. F. 0. F. 0.

Start 235. N2. 8 300 142. 9 220 104. 4 5'7, 206 146. 7 3 .5 157. 2. 290 143. 3 10% 3l0 154. 4 323 161. 7 306 152. 2 20% 33!) 165. 6 3 3 172.8 332 160. 7 30%. 340 17]. l 361 182. 8 345 173. 9 40%. 358 18!. l 383 195. 0 366 185. 8 50%. 371 183. 3 400 204. 4 377 191. 7 60%. 386 196. 7 417 2l3. 9 398 203. 3 70% 401 205. 0 439 226. l 407 208. 3 80% 416 213. 3 461 238. 3 435 223. 9 90%. 441 227. 2 491 25 5.0 470 243. 3 92%.. 512 266.7 Gravity, A. P. I 37. 7- 37. 3 20. 7 SD. Lr. at 1550 C 0. 830 0. S38 0. 878 Viscosity at 10 F. (378 0.):

Universal Saybolt, secs. 255 105 Redwood, secs... 161 2m 90 Engler No 5. 63 7. 50 3 16 Unsulionnted residue percrmL 8 8 100 highly refined petroleum oils (for example, those of the 100% unsulfonated residue" type) hav found adaptation. For example: i

A group of lemon trees, in the flowering and fruiting season, was treated with the aliphatic olefine spray oil identified as Olefine Spray Oil No. 2 in the tabulation above, in the form of a two percent emulsion in water, in the ordinary manner, with the addition of a small amount-of a spreading and wetting agent. A second group of trees in the same grove was treated at the same time and under identical conditions with a two percent emulsion of the highly refined petroleum oil identified as 100% Unsulfonated Residue Naphthene Base Spray Oil in the tabulation above. All of the trees treated were severely infested with California Red Scale and were moderately infested with Red Spider. After 60 days, mortality counts were made: On heavily infested fruits, mortality with the olefine oil was 97.1%; mortality with the 100% unsulfonated residue oil was 93.3%. On heavily infested twigs, mortality percentages were nearly identical for the two oils, 76.4% and 76.7%, re-. spectively. The tree reactions in general. as regards leafand fruit-drop, were normal in all cases. Six months after the treatment. both groups of trees were again examined and were found normal in every respect.

As has been noted above, oleflnic oils of any desirable or suitable viscosity and or boiling point range may be obtained by fractionation of the olefine polymers first produced. As principally described hereinbefore, these olefine polymers are advanta eously prepared by the use of anhydrous aluminum chloride as catalyst, but other polymeriz ng catalysts, such as anhydrous ferric chloride and boron trifiuoride, may likewise be employed. Strong phosphoric acid, either as such or upon fusion with siliceous adsorbents, may also be employed as polymerizing catalyst when gaseous olefines are employed as initial materials; these catalysts produce polymers largely boiling below the usual spray oil range, however, with only lesser quantities of such viscosity and volatility as make them adaptable for parasiticidal spray purposes. In all events, the initial olefinecontaining materials should be substantially freed from sulfur-containing compounds and from such hydrocarbons as produce cyclic unsaturated or aromatic hydrocarbons upon polymerization or condensation; the polymerization catalysts and conditions of polymerization should likewise be chosen so that cyclic unsaturated and aromatic hydrocarbons are not formed, for, as has been pointed out, the acyclic olefine hydrocarbons characterized by the presence of one double carservice, these olefine spray oils, of spray oilviscosity and volatility, form far smaller quantities of phytocidal oxidation and polymerizationproducts (that is, asphalty bodies and asphaltog'enic acids) than are formed upon similar exposure of highly treated petroleum spray oils. Attention has already been called to the very high viscosity of.

these olefine oils, as compared wlth'the petroleum oils, for equivalent boiling point (volatility) range, and the significance of increased viscosity together with high volatility in parasiticidal oils has been noted above.

'It should be noted that olefines with boiling points above about 600 F. (315 C.) at 3.5 millimeters of mercury pressure should not be present in the spray oils as applied to foliage; olefines boiling above that point should be segregated and discarded, as in the fractionation operation described, for it has been found that such high boiling oleflnes or polymer fractions have so low a vapor pressure and volatility as to remain too long on the foliage, detrimental to plant physiological processes and prejudicial to the appearance and cleanliness of fruit and foliage.

The olefinic spray oils here described may be blended or admixed with well refined petroleumderived spray oils of the type now in wide and accepted parasiticidal use, if desired, and such blends may be of advantage in particular instances where certain viscosity and volatility characteristics are sought, not easily obtained by the application of either type of spray oil alone; in such blending, the refined petroleum spray oil component should have an unsulfonated residue of at least 85%, for summer spray applications. Likewise, the olefine oils may be blended with more volatile, less viscous products either of the same type or of the type of well refined kerosenes, where Wide coverage of insect and foliage with very thin ultimate films is desired: the lower cost of the more volatile diluents often makes possible more economical insect kills and avoids the application of thick films of viscous oil to sensitive plant foliage. In dilution of this sort, the olefine oils may be diluted with from one to as much as ten times their volume of the more volatile and less viscous oil, as desired.

In general,-these olefinic spray oils are applied to the foliage harboring the insect or fungus pests in emulsified or in finely-divided mist orfog-like form, in operations found acceptable with the use of highly refined petroleum oils for the same purposes.

In applying the oils in unemulsified form, either as such or diluted with a less viscous oil-miscible diluent such as kerosene, it is preferable to employ a device which disperses the liquid in the form of droplets of sizes within the approximate range 0.07 to 0.30 millimeter in diameter, in an ,air stream of large volume and high velocity but of low pressure, directed into and around the foliage to be enveloped. Droplets of smaller diameter than 0.07 millimeter tend to float away and dissipate in the atmosphere, with consequent loss of oil and ineffectual contacting of parasites, while droplets of greater than 0.30 millimeter diameter tend to drench the foliage and the pests with an unnecessary amount of oil, wasteful and sometimes injurious to the vegetation. In the absence of devices capable of producing droplets largely within this preferable size range, these olefine oils may be applied as sprays in the manner common with petroleum sprays, observing the same precautions asare there understood.

For application to plant pests in emulsions in water. it is preferable to employ the olefine oils in concentrations of between 1 and 4% but concentrated stock emulsions and soluble oils or miscible oils containing from -95% of oil may be prepared and stored, for 'later dilution with water at thetime of parasiticidal application. Thus alkali metal or lime caseinate" with smaller amounts of soda or potash fatty acid soaps may be used in preparing stock emulsions, and the alkali metal soaps of either oil-soluble or water-soluble sulfonic acids derived in the treatment of petroleum lubricating oil distillates with strong sulfuric acid, alcoholic potash phenol and rosin soaps, partially hydrolyzed esters of glycerol and higher fatty or naphthenic acids, and the like, may be employed in preparing mixtures which emulsify readily upon the addition of water, with agitation. In the employment of sodium soaps of petroleum sulfo'nic acids. for example, 2% thereof in olefine oil solution provides a ready emulsion in 50 times its volume of water. Likewise, oleic or similar fatty acids and fatty oils may be dissolved in the olefine spray oils, in small amounts, and emulsification in water brought about by addition of this mixture to a prepared water in which has been dissolved a caustic alkali or carbonate or even a neutral water-soluble soap.

The olefine spray oils are compatible with stomach poisons such as lead arsenate, Bordeaux mixture and lime-sulfur solutions; if such poisons are applied together with emulsions of the oils a suitable wetting and spreading agent or mixtures thereof will insure evener and more effective distribution on the foliage: alkali caseinates, glue, gelatin, soap bark, dextrine, gamboge, blood albumen, water soluble sulfonic acids and molasses are suitable spreading and stabilizing agents for this purpose. These oils or emulsions thereof may likewise be employed in conjunction with nicotine extracts and with extracts or infusions of derris or cube, rotenone, pyrethrum and the like, in the amounts and in the manner in which they have been employed in conjunction with spray oils of the highly refined petroleum type spray oils.

While the character of the invention has been described in detail and numerous examples of its employment and application given; this has been done by way of illustration and with the intention that the invention shall not be limited thereto.

I claim:

1. A parasiticidal oil consisting substantially,

entirely of liquid aliphatic mono-olefine hydrocarbons, the said olefine hydrocarbons boiling in major part above about 235 F. and below about 600 F. at 3.5 millimeters mercury pressure.

2. A parasiticidal oil consisting substantially entirely of liquid aliphatic mono-olefine hydrocarbons boiling within the range 235 to 600 F. at 3.5 millimeters mercury pressure.

3. A parasiticidal composition comprising liquid aliphatic mono-olefine hydrocarbons boiling in major part above about 235 F. and below about 600 F. at 3.5 millimeters mercury pressure, in the substantial absence of cyclic unsaturated and aromatic hydrocarbons.

4. A parasiticidal composition comprising liquid aliphatic mono-olefine hydrocarbons boiling within the range 235 to 600 F. at 3.5 millimeters mercury pressure, in the substantial absence of cyclic unsaturated and aromatic hydrocarbons.

5. A non-phytocidal parasiticidal composition for application in liquid spray form to plant foliage comprising liquid aliphatic mono-olefine hydrocarbons boiling in major part above about 235 F. and below about 600 F. at 3.5 millimeters mercury pressure, in the substantial absence of cyclic unsaturated and aromatic hydrocarbons. .6. A non-phytocidal parasiticidal composition for application in. liquid spray form to plant foliage comprising an admixture of liquid aliphatic mono-olefine hydrocarbons with from one to ten times their volume of a more volatile non- 75 phytocidal hydrocarbon diluent, the said olefine hydrocarbons boiling in major part above about 235 F. and below about 600 F. at 3.5 millimeters mercury pressure.

7. A non-phytocidal parasiticidal composition for application in liquid spray form to plant foliage comprising an admixture of liquid aliphatic mono-olefine hydrocarbons with an emulsifying agent, the said olefine hydrocarbons boiling in major part above about 235 F. and below about 600 F. at 3.5 millimeters mercury pressure.

8. A non-phytocidal parasiticidal composition for application in liquid spray form to plant foliage comprising an admixture of liquid ali-- phatic mono-olefine hydrocarbons with a petroleum horticultural spray oil, the said olefine hydrocarbons boiling in major part above about 235 F. and below about 600 F. at 3.5 millimeters mercury pressure and the said petroleum spray oil having an unsulfonated residue of at least 85%. e

9. A method of combatting plant parasites residing on plant foliage comprising applying to the foliage a non-phytocidal liquid spray containing liquid aliphatic mono-olefine hydrocarbonsboiling in major part above about 235 F. and below about 600 F. at 3.5 millimeters mercury pressure, in the substantial absence of cyclic unsaturated and aromatic hydrocarbons.

10. A method of combatting plant parasites residing on plant foliage comprising applying to the foliage a non-phyto'cidal liquid spray containing liquid aliphatic mono-olefine hydrocarbons boiling within the range 235 to 600 F. at 3.5 millimeters mercury pressure, in the substantial absence of cyclic unsaturated and aromatic hydrocarbons.

' ARTHUR L. LYMAN. 

